Food for Thought

Don't stop at fueling your body for peak performance. You need to feed your brain to smash those PRs.

As runners, we expend plenty of mental energy thinking about the right foods to fuel our bodies. But what about fueling our minds? The brain is a key organ in running performance, and to function at its best–when you need it most–it also needs the right nutrients.

When legs get heavy, it takes a lot of brain-power to keep the body moving. So how can you harness the psychological strength of a winner? According to the latest science, the right foods could give runners a mental edge.

"The most important micronutrient is the one that's missing from your diet," says Alex Hutchinson, former elite runner, scientist and Runner's World "Sweat Science" columnist. But he doesn't recommend supplementing to get any particular one. "To run your best," he says, "you need to make sure you're covering your bases with a diverse diet that gives you enough of key micronutrients like creatine, DHA and nitrates."

Emily Brown, former U.S. cross country champion and registered dietitian, agrees. "As a runner, I know we sometimes get too focused on looking for the one thing to give us that edge," she says, "As a dietitian, however, I am most concerned about balance and variety in the overall diet. Eating a wide variety of healthy foods will likely provide runners with all they need of these nutrients."

Turn the page to learn the foods in your cup-board that pack the nutrients your brain needs.

The Concentration SharpenerDOCOSAHEXAENOICACID

WHY: About 50 percent of the human brain is made of fat, of which a large portion is docosahexaenoic acid (DHA), but this supercharged omega-3 cannot be made by the body and comes solely from dietary sources. This matters because studies show DHA plays a big role in boosting mental focus and concentration levels during exercise. "DHA makes brain cells more receptive to messages from neurotransmitters," explains U.K. nutritionist Carrie Ruxton, who has a doctorate in child nutrition.

HOW: Eating eggs to power up on protein is a no-brainer, but they're a great source of DHA, too. Go for an egg and avocado sandwich for a powerful protein/fatty-acid combo. Research published in the Journal of Applied Physiology found 6 grams a day delivers enough DHA to improve performance.

The MessengerCHOLINE

WHY: Despite evidence to the contrary on the dance floor, your legs don't have a mind of their own. When running, they rely on the brain sending acetylcholine demands via nerve cells to the muscles. But without choline, your body can't produce this chemical messenger. Research published in the International Journal of Sports Medicine shows that blood-choline levels drop by as much as 40 percent in the latter miles of a marathon. Consequently, scientists say that low choline could contribute to long-distance fatigue.

HOW: The National Academy of Sciences' adequate intake (AI) standards for choline are 550 milligrams for adult males, 425 milligrams for females. You can get nearly all of that from 5 ounces of beef liver, or about a third of it from one egg, a quart of milk or 4 ounces of shrimp. Vegetarian sources include collard greens, Brussels sprouts and broccoli–each provides around 70 milligrams per cup.

The MotivatorNATURAL NITRATE

WHY: Research from the University of Exeter in the U.K. shows high levels of nitrate, found in beet-root, are converted into nitric oxide. Nitric oxide widens blood vessels, and further findings from Wake Forest University show this may have a direct effect on mental power by boosting blood flow to the frontal lobe, an area of the brain linked to motivation and attention span.

HOW: Have two beet-root juice shots (about 0.6 grams of nitrates each) a few hours before speed work, or four shots before a distance run. Exeter University research suggests the effect of nitrate peaks two to three hours after consumption. Not a beetroot fan? Swedish researchers found that taking nitrate as a supplement works, too, but warn of potential dangers with improper dosage. Rhubarb and arugula are also good sources.

The Motion ControllerALPHA-LINOLENIC ACID

WHY: According to experts, alpha-linolenic acid (ALA), a type of omega-3 fatty acid, improves the functioning of the cerebral cortex, an area of your brain associated with spatial awareness and motor skills. "ALA is important for brain health," Ruxton says. "Plus, it has the added benefit of acting as an anti-inflammatory."

HOW: Sprinkle 1 or 2 teaspoons of ALA-rich flax-seeds on pretraining meals. "Milled flaxseeds taste better than the unprocessed variety and can be added to breakfast cereals and stews," Ruxton says. ALA is also found in peanuts, walnuts, zucchini and summer squashes.

The Brain FuelerGLUCOSE

WHY: Carb gels aren't just for your legs–the brain runs almost exclusively on glucose. "The brain is very sensitive to decreases in blood glucose concentration," says Martin Sellens, professor of sports and exercise science at the University of Essex in the U.K. "It might even cause the body to slow midrun to protect its supply." Backing this, recent University of Birmingham research found that 60-minute time-trial performance improved when athletes swished a sports drink and spat it out. The researchers concluded that sensors in the athletes' mouths sent signals to the brain announcing the impending fuel. The brain then allowed the body to go faster in anticipation.

HOW: While your muscles don't need extra carbs on runs of less than 90 minutes, your brain may benefit from regular sports–drink swilling during 45- to 75-minute runs. "Mouth rinsing with a 6.4 percent maltodextrin solution seems to work," Sellens says. "This is a similar concentration to most sports drinks." Also, keep glycogen stores stocked by eating low glycemic index foods, such as oatmeal, brown rice and strawberries.

The Focus MaintainerVITAMIN E

WHY: Research in the Archives of Neurology & Psychiatry suggests that the antioxidant can help maintain mental function until the final mile by protecting the brain from oxidative damage. "Blood-boosting fatty acids are prone to oxidation, leaving them ineffective," Ruxton says. "Vitamin E prevents this process." The result is that blood cells carry more nutrients to the brain, improving focus.

HOW: Walnuts have a winning combination. "They've got a unique blend of fatty acids and vitamin E that makes them particularly good for blood vessels in the brain," Ruxton explains. Researchers at Tufts University back this, finding that a moderate amount of walnuts daily can boost cognitive function. Positive effects are seen at intakes of 30 grams, so squirrel away 10 walnuts a day.

The Endurance BoosterTYROSINE

WHY: Released when protein is broken down, this amino acid is used to make performance-boosting neurotransmitters, including epinephrine, norepinephrine and dopamine. Research from Jerusalem University Medical School shows tyrosine also decreases brain levels of the fatigue-inducing 5-HT neurotransmitter, while scientists at Aberystwyth University in Wales found that athletes exercising in 85-degree heat took longer to reach exhaustion after drinking a tyrosine-rich drink one hour beforehand.

HOW: Preliminary studies suggest moderate doses of 100 to 660 milligrams per pound of body weight taken before exercising in extreme heat or cold can boost cognitive function. "But more research is required to prove the benefit of high amounts," says professor Romain Meeusen, head of human physiology at Vrije University in Brussels. "They might even be dangerous." Get your dose from a sprinkling of sesame seeds, or choose almonds or avocados.

The Mental-Fatigue BusterCREATINE

WHY: We already know it builds brawn, but now scientists at the University of Sydney and Macquarie University in Australia have discovered that increased creatine intake reduces mental fatigue and boosts cognitive performance. Great news for weary souls facing intense sessions after long days at the office.

HOW: Avoid large doses: "Creatine pulls water into the muscles, creating dead weight," Sellens says. Fortunately, research now shows that several small doses can be effective. Runners from Tartu University in Estonia took 6 × 5 grams of creatine daily and improved their 1K times. And, crucially, lower doses aren't linked to weight gain. Beef, salmon and tuna are excellent sources–every 8 ounces provides 1 gram of creatine. Herring provides nearly double that.

The EnergizerCAFFEINE

WHY: Caffeine can reduce your rate of perceived exertion (RPE), blunting the pain of high-intensity exercise, according to researchers at the University of Alabama. The legal stimulant reshapes the biochemical environment in the brain by blocking the release of adenosine, a neurotransmitter that stimulates relaxation. The result is that you feel energized, and your body's response to exhaustion is postponed.

HOW: Have 90 milligrams of caffeine–equivalent to a cup of filtered coffee–pre-run. A large dose doesn't appear to boost performance any more than a moderate dose of 4 to 6 milligrams per kilogram of body weight, but a study in the Journal of Applied Physiology found that regular coffee drinkers are less likely to feel the benefits. So save your daily dose for a pre-run kick.